Attempts to protect the human body or surfaces contacted by the human body from various airborne contaminants have taken many forms. Considerable use has been made of air purifiers to remove macroscopic contaminants. For this purpose, air ventilation systems in enclosed areas such as buildings generally include an air filter and/or an electrostatic precipitator. However, it is well known in the art, that while the quantity of contaminants that reach the space to be protected can be reduced by such means it is not possible to completely preclude the entry of small airborne contaminants having a diameter less than 10 xcexcm, such as bacteria, viruses and the like. As a consequence of ineffective air purification, harmful airborne agents are disseminated throughout the enclosed area and come into contact with exposed surfaces.
In order to overcome the problems associated with small airborne contaminants, filters have been developed with micron sized pore openings. However, due to the small nature of the pore openings these filters became clogged in a short period of time. In order to overcome this problem, an electrostatic charge has been applied to the surface of such filters for repelling particles rather than entraining them in the filtering medium. As an example, U.S. Pat. No. 5,863,312 describes a face mask for covering a wearer""s mouth, nose or both, with a single layer of non-entraining filter medium which may have an electrostatic charge applied to it for rejecting particulate matter rather than catching or entraining it. In addition, U.S. Pat. No. 5,492,551 describes a similar means for filtering air by electrostatic rejection.
U.S. Pat. Nos. 5,863,312 and 5,492,551 do not describe a method and apparatus for imparting some or substantially all of the airborne agents with a repellent charge. In the operation of the method and apparatus of these inventions, the air to be purified contained substantial amounts of: (1) uncharged airborne agents; (2) airborne agents with a repellent charge; and (3) airborne agents having an attracting charge with respect to the filter or mask. As such, not all of the airborne agents can be repelled away from the filter or mask. Therefore, the pore size of the filter medium was made to be smaller then the airborne agents for collecting them. In addition, in the use of the method and apparatus of these inventions, naturally occurring oppositely charged particles contained in the particulate laden air are attracted to and also accumulate on the electrostatically charged filter medium. The accumulation of both the neutral and charged particulate matter both clogs the pores of the filter and reduces the efficiency of repulsion by reducing or screening the electrostatic charge on the filter.
Another filtering system that used both rejection and collection of charged agents on a filter is given in U.S. Pat. No. 5,468,488. This patent describes a method and apparatus for restricting the flow of airborne contaminants into a nasal passage. In the operation of the method of U.S. Pat. No. 5,468,488 a spray solution is sprayed onto or around the nasal passages for providing for an electrostatic field. As with the two previously mentioned patents, it involves creating an electrostatic field that either repels or attracts airborne contaminants or both but does not provide for a method and apparatus for electrifying airborne agents with a repellant charge.
Other methods used in the past to shield humans from airborne contaminants have included the use of gas curtains and physical barriers such as surgical garments and masks. An example of the use of air curtains as protective shields is given in U.S. Pat. Nos. 4,140,105 and 4,471,688.
Currently, surgical garments and masks are used as the primary protection for operating room personnel. Surgical garments and masks are not intended to, and do not prevent, the spread of harmful substances and biogenic materials to all parts of the general operating room environment and do not protect certain parts of the practitioner. For example, such equipment often does not protect the eyes and other exposed parts of the body of operating room personnel from contact with fluids in the form of airborne aerosols including bone particles and liquids from direct sprays, streams, or splashes of liquids. Surgical garments that completely cover the body such as those that resemble astronaut""s space suit protect only the person wearing it and provide no protection to others in the room against airborne agents. The production of such airborne agents in medical facilities can cause contaminants to come into contact with the mucus membranes of the medical staff. Airborne agents of this type can contain live virus, including AIDS virus, when such is present in the patient. Accidental contamination with airborne aerosols of blood and body fluids of patients having other diseases, such as hepatitis B, may also be communicated by such a mechanism.
When using surgical equipment, the operator often must be able to move in many directions to get the correct point of contact or leverage to use the equipment. Conventional barriers, whether physical or air curtain often limit visibility and/or mobility and/or expose the operator to airborne contaminants. In particular, when using surgical and dental equipment, a medical practitioner must often work between the vacuum source or physical barrier and the operating site, thus exposing the practitioner to infection.
Non-shielding methods used in the past to protect humans from airborne contaminants have included the use of vacuums as described in U.S. Pat. Nos. 3,537,447 4,650,171 and 5,215,539.
Vacuum devices positioned on the instrument itself typically limit the area of protection, as the vacuum only draws in air from the area nearest to the tool. Finally, vacuum devices currently in use and having self-contained vacuum source are often limited in application, as such devices incorporate no means for the containment, destruction, or safe evacuation of contaminants. Such devices are inappropriate for protection from hepatitis and AIDS, as those viruses are dangerous in low concentrations and could be carried to remoter sites by an evacuation system that does not remove contaminants from the gas stream.
In many medical situations open wounds, ulcers, and burned tissue are exposed to airborne agents. As such, wounds and skin ulcers can become contaminated by airborne microorganisms, both pathogenic and non-pathogenic types. Wounds that are heavily contaminated by microorganisms, but not clinically infected, are often characterized by a prolonged period of inflammation as well as a delay in wound repair and healing.
Present shielding systems and other methods for protecting humans from airborne contaminants are inadequate for removing all of the pathogen carrying aerosols produced in a medical procedure. Current air purifiers do not remove bacteria and viruses and provide no protection at all against airborne contaminants in spaces where airborne contaminants are produced, such as medical and dental consultation rooms, operating rooms and the like.
It is an object of the present invention to provide for a method and apparatus for protecting an exposed surface contained in an enclosed space from harmful airborne agents that may be unintentionally produced.
It is another object of the present invention to provide for a method and apparatus for maintaining a repellant charge on an exposed surface for repelling oppositely charged particles.
It is still another object of the present invention to provide for a method and apparatus for collecting and destroying harmful airborne agents.
It is a further object of the present invention to provide for a method and apparatus for confining potentially harmful airborne agents to the smallest area possible and thus, minimize its dissemination and ultimate spread to other areas or to humans.
It is a still further object of the present invention to provide an improved method of and apparatus for shielding a patient or a medical practitioner from pathogen carrying aerosols produced by a patient during a medical operation.
It is also an object of the present invention to provide for a method and apparatus for protecting an exposed surface from airborne agents which can be done solely by electrostatic means and apart from any other known method of protecting an exposed surface such as by filtering, physical barriers, air curtains and vacuum systems and without the need for the movement of air by such devices as pumps, fans and the like.
In addition, it is an object of the present invention to provide for a method and apparatus for filtering harmful airborne agents from a gas such as air by subjecting the airborne agents to a charging means for charging the agents with a charge of single polarity and charging a filter, which may have pore openings larger than the agents the be filtered, with a like charge for filtering a flow of air.
Definitions
As used herein the word xe2x80x9cwoundxe2x80x9d is intended to include: surgical incisions, abrasions, cuts, punctures, blemishes, tears, sores, blisters, burns, contusions, tissue ruptures and the like. As used herein the words xe2x80x9cexposed surfacesxe2x80x9d are surfaces that are either part of the human body or are surfaces that come into intimate contact with the human body during normal use and as such transmit, pass or otherwise act as a source for toxic, harmful or infectious airborne agents to humans.
As used herein, the words xe2x80x9cbiogenic particlesxe2x80x9d are particles of biological origin. They include viable entities such as bacteria, fungi, viruses, amoebae, algae, and pollen grains and the no-longer-viable forms of the same. The also include plant parts; insect parts and wastes; animal saliva, urine, and dander; human dander; and a variety of organic dusts. As used herein the word xe2x80x9cshieldxe2x80x9d means to deflect a moving airborne particle from its original path as a shield deflects an arrow.
This invention relates to the protecting of exposed surfaces that can transmit, pass or otherwise act as a source of toxic or infectious airborne agents to humans such that humans become infected or contaminated by the airborne substance. In particular, this invention relates to the protecting of exposed surfaces from noxious airborne agents such as, but not limited to, (1) industrial particulates, (2) infectious matter such as bacteria, viruses, fungal spores, and aerosols that may carry these infectious agents, (3) potential disease carrying aerosols produced from blood and other bodily fluids, small particles of skin, fat, muscle tissue and bone, (4) particles which may be emitted from a human body such as respiratory droplets, skin squamae, and hair, (5) allergenic materials such as pollen, spores, and animal dander, (6) caustic agents such as airborne acids and bases and (7) aerosols used as chemical or biological warfare agents. More particularly, this invention relates to the protecting of exposed surfaces from toxic and/or infectious airborne agents where the protecting of such surfaces for health and safety reasons is desirable and an unobstructed manual access is necessary.
The present invention is useful for controlling the spread of E. Coli, salmonella and other pathogens from the surfaces of foods by airborne agents. In particular, the present invention is useful for protecting exposed surfaces such as meat and meat products and surfaces that come into contact with the same from pathogen carrying airborne particles produced in slaughter houses and the like.
The present invention is also useful for protecting exposed animate surfaces such a humans or part thereof such as, but not limited to, skin, lungs, eyes, mucus membranes and wounds from harmful airborne agents. In particular, this invention is useful for protecting the exposed surfaces of patients and medical staff from noxious airborne agents. More particularly, this invention is useful for the protecting of patients with reduced immune responses from such conditions as AIDS or have an increased risk of infection due to such conditions as illness, wounds or surgical wounds. In addition, the present invention is useful for protecting exposed inanimate surfaces, such as polymeric materials, glass, rubber, metal, food and drugs, that come into intimate contact with humans such that they can transmit, pass or otherwise act as a source of toxic or infectious airborne agents to humans. In particular, the present invention is useful for protecting inanimate surfaces such as, but not limited to, medical equipment, food, food handling equipment, drugs and drug handling equipment.
Furthermore, the present invention is useful for protecting exposed surfaces from harmful airborne agents produced unintentionally by or during human activity. In particular, the present invention is useful for protecting exposed surface from harmful airborne agents produced by or during the following activities: (1) the operation of medical tools such as high speed drills, saws, reamers, and cutting equipment and other tissue removing implements, (2) the release of contaminants from various medical procedures such as the insertion or withdrawal of tubes and other medical procedures wherein an instrument is brought into physical contact with bodily fluids; (3) the release of contaminants as by suctioning or by irrigation; and (4) the release of emitted particles such as respiratory droplets and skin squamae from infected patients during breathing or movement of the body.
The present invention is applicable to the protecting of exposed surfaces from airborne agents in reduced spaces as found in buildings. In particular, the present invention is applicable to the protecting of exposed surfaces from airborne agents in buildings such as hospitals, medical and dental consultation rooms, laboratories, drug manufacturing plants, food production facilities and the like. In addition, the present invention is applicable to the protecting of exposed surfaces from airborne agents in reduced spaces as found in vehicles. In particular, the present invention is applicable to the protecting of exposed surfaces from airborne agents in vehicles such as ground craft, aircraft, spacecraft, marine craft and the like.
The present invention provides for a method and apparatus for protecting an exposed surface from harmful airborne agents, comprising the steps of: subjecting the airborne agents to a charging means for placing one particular charge type, which can be either positive or negative, on the agents; and placing an electrostatic charge on or near the exposed surface for moving, by a repellant or attracting force, the charged airborne agents from the exposed surface for protecting the surface.
The present invention also provides for a self-contained, portable and prefabricated apparatus adapted to be assembled within the confines of a preexisting structure or room, such as a hospital room, operating room, or medical or dental consultation room for confining, collecting and destroying airborne pathogens. The apparatus comprises: a charging means for forming charged species; a moving means for moving the charged species through an area where pathogen containing airborne agents are being produced for bringing the charged species into intimate contact with the airborne agents for combining with, transferring their charge to, or otherwise electrifying the airborne agents; a collection means for collecting charged airborne agents; and a pathogen destruction device for destroying the collected airborne pathogens. A barrier can be placed around the worldling area for further restricting the airborne agents. The barrier can be charged for repelling charged airborne agents. An insulated floor can be provided for insulating objects or persons inside the apparatus.
The present invention provides for a method and apparatus for electrostatically charging aerosols produced by a medical tool such as a drill, saw, reamer and other aerosol producing tools. The aerosol ionizer is useful for charging aerosols produced by medical tools, in particular, electric medical tools such as drill, saws, reamers and other tissue removing devices for their subsequent collection and destruction.
In addition, the present invention provides for a method and apparatus for electrifying an exposed individual, such as a patient or medical staff member, from repelling harmful airborne agents. The method comprises the following step: (1) an individual to be electrified is placed in an airtight booth; (2) the individual is sprayed with a charged matter of single polarity, such as an aerosol, droplets and the like for charging the individual with a single polarity; (3) the individual exits the booth and enters into a room of higher pressure containing charged airborne agents having the same polarity.
Furthermore, the present invention provides for a method and apparatus for electrifying an exposed surface for repelling charged airborne agents comprising; a power supply for applying a voltage of between 0 and 50,000 volts to an object for protecting the exposed surface and with a current of between 1 and 5 micro amperes.
The advantages of the present invention in shielding exposed surfaces over prior art include:
1. Can protect exposed surfaces from small airborne agents having a diameter less than 10 xcexcm.
2. Can repel substantially all airborne contaminates from a mask for improving the efficiency, the operational life, of the mask and for increasing the size of the pores for easier breathing and reduced manufacturing costs.
3. Can protect the eyes, mucous membranes, wounds and other exposed surfaces of medical staff and patients without the need for spacesuit style clothing.
4. Can confine medically produced aerosols to confined areas to minimize its dissemination and ultimate spread to other areas or humans.
5. Can provide for the containment, destruction, and safe evacuation of airborne contaminants.
7. Can provide for safe medical and dental care to patients without treating the patient as some type of disease carrier.
8. A practitioner is allowed full freedom of movement relative to holding and moving tools, as the electrostatic fields operate as such that the practitioner does not have to work under or around a physical shield. Also, visibility of the operating site is maintained due to the transparent nature of electrostatic fields.
9. Allows for the passage of air over a wound for exposing the wound to an oxygen rich environment for increasing the rate of healing, while repelling infectious airborne agents.